Special Containment Procedures: SCP-2138 is contained in a pressurised canister, sealed inside an air-tight box. The box is stored in a standard containment locker at Site-73. Pressure sensors inside the canister are programmed to notify staff in case of any leak.

Response to any leak, or any other activity requiring the containment locker to be opened, is to be carried out by Level-1 personnel trained to operate the site's industrial vacuum system. In the event of containment breach by SCP-2138, all personnel with Level-3 security clearance and higher are to be evacuated from Site-73 immediately. Any persons exposed to SCP-2138 are to be quarantined in isolation pending Site Director instructions.

Research on SCP-2138 has been terminated following Incident SCP-2138-1. As a result of Incident SCP-2138-2, no instances of SCP-2138-A are available for further study.

Description: SCP-2138 is a light blue, odourless, gaseous substance of unknown composition. The substance is chemically inert with normal atmospheric gases, is not flammable, and exhibits a rapid rate of diffusion. Initial gas chromatography results were inconclusive, and further physical and chemical properties of SCP-2138 have not been established. SCP-2138 was generated as a by-product of Dr Isaacs' attempts to synthesise a less harmful alternative to current psychoactive substances used as "truth serums" in Foundation field work.1

Exposure to or inhalation of SCP-2138 results in no harmful physical effects on animal specimens tested, but humans exposed to the substance exhibit the anomalous effect referred to as SCP-2138-A. Whether SCP-2138 has the same anomalous effect on all sapient entities is unknown.

SCP-2138-A consists of the appearance of a dark rectangular shape (approximately 45 x 30 cm) above the subject's head. The shape displays a series of short statements in bright yellow text, with the series repeating over time. Each statement discloses information known to the subject alone, or to the subject and a limited set of others. The effect appears to be permanent, although a change in the subject's knowledge will affect the content of the statements displayed. SCP-2138-A is invisible to the subject, and attempts to interact physically with SCP-2138-A appear to be harmful to the subject.

SD-73: Recording now. This is Site Director Garcia, noting for the record the outcome of my discussion with Dr Jan Isaacs following Incident SCP-2138-1. As discussed, Dr Isaacs, your involvement in the incident has given rise to what I could euphemistically call a human resources issue. For obvious reasons, we haven't been able to include HR representatives in this meeting - that's also why we're using audio recording, and not video.

Dr Isaacs: This is Dr Isaacs. For the record, I confirm that this approach has my full consent.

SD-73: So, where should we start?

Dr Isaacs: Well, our debate on the relative ethical merits of the use of clearance to adjust experimental assignments versus D Class treatment in general was, well, spirited, but let's gloss over that, shall we?

SD-73: Agreed. I think your current condition is more than sufficient punishment for any infractions in that regard. So, then we discussed the fact that you are now a serious security risk for this site, and the Foundation in general.

Dr Isaacs: You can't let me leave, nor can I work or interact with anyone without my current broad clearance. Basically you said you want to stick me in containment.

SD-73: That's not what -

Dr Isaacs: Sorry Alex, that was unfair. You didn't say that, but that doesn't change what it means from my perspective. You were offering me permanent residence at Site-73, in total isolation. We discussed in detail the likely psychological effects.

SD-73: We did. And in recognition of that fact, I offered you the chance to spend time with your family.

Dr Isaacs: On the condition that they live here permanently too! I mean, how did you think I could put my kids through living in this place, with the risks that we run every day, the -

SD-73: - you know that this site has the Foundation's cleanest record in terms -

Dr Isaacs: - and how could I look at them and tell them they have to leave their friends, their lives -

SD-73: - a larger purpose to consider. Jan. Jan! I don't think we need to rehash this again.

Dr Isaacs: I'm sorry, Alex, but that's easy for you to say. It's not your life.

SD-73: It wasn't my choice that led to this. Look, we've worked together a long time. Are you sure about this?

Dr Isaacs: I'm sure. Having discussed at length, I have requested that, in lieu of contai- in lieu of quarantine or termination, I am to be given an F-Class amnestic.

SD-73: I'd like to record a formal caution on this request - Jan, you know that it won't be you any more. It's a total personality overwrite.

Dr Isaacs: I know. But my new personality won't know any of the secrets I'm revealing now - I won't be a security risk. And I'll live. I mean, the whole point of this research in the first place was to avoid unnecessary harm.

SD-73: We still won't be able to let you leave.

Dr Isaacs: No, but I won't go mad thinking of the life that was taken away from me, and perhaps I can be of some use. Make me a clerk, or a janitor. Even a D Class.

SD-73: Okay, then. I formally grant the request. Dr Isaacs will be given an F-Class amnestic and reassigned based on the replacement personality. For all external and internal purposes, this will be treated as death in the course of meritorious service to the Foundation, with full benefits to the family. This recording is to be treated as Clearance 4/General-73.

Dr Isaacs: Thank you, Site Director. Alex.

SD-73: Jan, before we finish. What you've done for the site, over the years. I want to say - what you have been trying to do, I - I respect it. I - anyway. Ah, I guess I'll call the amnestics team. We can stop recording now.

6:34 PM: A minor riot was reported during the return of Class D personnel to quarters following the completion of daily testing. Security personnel have attested that the inciting factor was a violent assault by D-4435 on D-13962. D-13962 later died of his injuries. One other Class D (yet to be designated an identification number) suffered a fatal heart attack whilst intervening in the riot, and fifteen Class D personnel were injured.

Footnotes

1. Dr Isaacs' research notes are classified, and are available to personnel with 2138/4 clearance.

2. Comprising a series of further statements revealing Level-4 classified information.